Cement retaining shoe



Jan. 10, 1956 A. K. KLINE 2,730,177

CEMENT RETAINING SHOE Filed Dec. 25, 1955 4; l j 4/: 1 'FEZQLMIZ & wk

\ w La ATTORNEYS United States Patent 2,730,177 CEMENT RETAINDJG SHOE Albert K. Kline, Tulsa, Okia.

Application December 23, 1953, Serial No. 400,037 2 Claims. (Cl. 166184) This invention relates to equipment for wells such as oil or gas Wells, and more particularly to a cement retaining shoe for a well.

The object of the invention is to provide a cement retaining shoe which utilizes a clockwise motion of the casing to expand the pack oil element against the well bore.

Another object of the invention is to provide a cement retaining shoe which includes a plurality of springs which act as a holding device to hold the packer in position while the pipe is rotated, the springs also acting as a centralizer to center the tool in the hole.

A further object of the invention is to provide a cement retaining shoe which is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same:

Figure 1 is a perspective view showing the cement retaining shoe of the present invention mounted in a well.

Figure 2 is a longitudinal sectional view taken through the present invention.

Figure 3 is a top plan view of the shoe.

Figure 4 is a sectional view taken on the line 44 of Figure 2.

Figure 5 is a sectional view taken on the line 5-5 of Figure 2.

Figure 6 is a sectional view taken on the line 66 of Figure 2.

Referring in detail to the drawings, the numeral 10 designates a well which may be a gas or oil well or the like, Figure 1, and the present invention is directed to a cement retaining shoe. The cement retaining shoe of the present invention includes an upper sliding ring member 11 which is adapted to receive therein a portion of a pipe 12, broken lines Figure l. Secured to the ring member 11 is a plurality of friction springs 14, the springs 14 being secured to the ring member 11 by suitable socket head screws 15.

Positioned below the ring member 11 is an adapter 16 which is provided with a plurality of spaced ports 17, Figure 2. The upper interior portion of the adapter 16 is threaded interiorly as at 18 for engagement with the lower portion of the pipe 12. The lower inner portion of the adapter 16 is also threaded as at 19, and arranged in threaded engagement with the portion 19 is a mandrel 20. A floating ring 21 is positioned above a rubber packer 25, and the floating ring 21 is secured to a split ring 22 by welding as at 23. The split ring 22 is rotatably mounted in a recess or annular groove 24 in the outer surface of the adapter 16. The lower ends of the friction springs 14 are secured to the floating ring 21 by suitable securing elements such as screws 26.

The mandrel is provided with an opening 27, and a pin 28 extends through the floating ring 21 and through the opening or slot 27, the pin 28 being secured to the outside of the ring 21 as by welding. Threadedly connected to the lower end of the mandrel 20 is a bottom shoe 29 which is provided with a valve seat 30 that is engaged by a ball 31. Communicating with the valve seat 30 is a flaring opening 32. A pin 33 extends through the shoe 29 and into engagement with the lower portion of the mandrel 20.

From the foregoing it is apparent that a cement retaining shoe has been provided for use in a well such as the well 10. A section of pipe such as the pipe 12 can be attached to the shoe through the medium of the threads 18. A clockwise motion of the casing is utilized to screw down against the pack olf element 25 to expand the element 25 outward against the well bore. The springs 14 act as a holding device to hold the packer in position While the pipe 12 is rotated, and the springs 14 also act as a centralizing medium or means to center the tool in the hole.

In use the cement retaining shoe is attached to the casing string 12 by slipping the casing string through the slip ring 11 and screwing the string into the adapter 16. The shoe is then run into the hole on the bottom of the casing to the point where the casing is to be cemented. The casing string is then rotated in a clockwise direction and this clockwise rotation of the casing turns the adapter 16 which screws the mandrel 20 upward. Rotation of the mandrel is prohibited by the pin 28 which extends through the slot 27 in the mandrel 2d. The pin 28 is fastened to a floating ring 21, and rotation of the ring 21 is prohibited by friction springs 14 which are attached to the ring 21 and which provide suflicient force against the wall of the hole to prevent this rotation. As the mandrel 20 moves upward, tension is applied to the bottom shoe 2-9. As the distance between the bottom shoe 29 and the slip ring 21 is shortened, the rubber packer 25 will be expanded outwardly to pack oil the area between the wall of the hole and the cement retaining shoe. After this pack off is etfected, the drillable ball 31 is dropped down the casing and comes to rest on the seat 30. After the ball has seated, the cement is pumped down the casing.

Movement of cement through the bottom of the shoe 29 is prevented by the ball 31 to thereby limit outward movement of the cement to the port holes 17. As the cement comes out of the shoe it is retained above the rubber packer 25 to thereby prevent cement contamination with the sand face below the cement retaining shoe. The cement remaining in the casing and the cement retaining shoe can be drilled out together with the drillable ball 31 and the inside of the drillable shoe 29.

The ball 31 is dropped after the shoe is set instead of being run in place since it is desirable to keep the shoe open going into the hole. If difliculty is encountered in lowering the easing into the hole, fluid can be then pumped down through the shoe to wash away any mud or the like that may be preventing casing movement. The shoe 2) is shaped as shown in the drawings so that after the inside of the shoe is drilled out a bevel remains on the outside and this bevel guides the re-entry back into the shoe of any tools run below it.

I claim:

1. In a cement retaining shoe, an upper ring member, a hollow mandrel positioned below said ring member and provided with an upper exteriorly threaded portion, an adapter having its lower end threadedly engaging plurality of ports, there being an annular groove in said adapter, a split ring rotatably seated in said groove, a floating ring positioned below said adapter and secured to said split ring, resilient means connecting said ring member to said floating ring, a resilient packer mounted on said mandrel, and a bottom shoe connected to the lower end of said mandrel, there being a valve seat in said bottom shoe, and a ball arranged in engagement with said valve seat, said resilient means comprising a plurality of spaced apart friction springs, there being a slot in said mandrel, and a pin extending through said floating ring and into said slot.

2. Ina cement retaining shoe, an upper ring member, a mandrel positioned below said ring member and provided with an upper threaded portion, an adapter threadedly engaging said mandrel and provided with a plurality of ports, there being a groove in said adapter, a split ring rotatably seated in said groove, a floating ring positioned below said adapter and secured to said split ring, resilient means connecting said ring member to said floating ring, a resilient packer mounted on said mandrel, a bottom shoe connected to said mandrel, there being a valve seat in said bottom shoe, a ball arranged in engagement with said valve seat, said resilient means comprising a plurality of friction springs, there being a slot in said mandrel, and a pin extending through said floating ring and into said slot.

No references cited. 

